1. Field of the Invention
The present invention relates to a photographic printing method and more particularly to a photographic printing method which determines a print exposure amount so as to optimize the print density of the primary subject by using photographic data recorded at a time of photographing the image.
2. Description of the Related Art
In making photographic prints, it is known to first determine a basis print exposure amount based on an average density of each original frame recorded in photographic film, for example, LATD (Large Area Transmitting Density), and to then calculate an exposure correction based upon data representative of characteristics of each scene of the original frame, in order to determine a suitable print exposure amount. The suitable print exposure amount is determined by statistical analysis in such a photographic printing method.
Although it is necessary to correct the print exposure amount when the density of a primary subject on the photographic film differs greatly from the average density of the whole area of the original frame including the primary subject, it is impossible in the above-described conventional photographic printing method to precisely detect the primary subject density on the photographic film because the position of the primary subject within the original frame is not always the same.
Therefore, it is hard to determine a proper correction of the print exposure amount. When the primary subject is disposed out of a central area of the original frame, it is even more difficult to determine the primary subject density on the photographic film, and hence the precision of the correction is lowered.
Furthermore, even when the original frames have been taken with a camera having a high-precision exposure control device, conventional print exposure determination is not affected. As a result, there is almost no difference in exposure accuracy between the photographic prints made from original frames taken by low-performance cameras, on one hand, and the photographic prints made from original frames taken by high-performance cameras.
Recent cameras have a high-precision automatic exposure control system allowing images of the subjects to be automatically photographed at a proper exposure value. For example, the exposure value of the camera is automatically determined in accordance with the brightness of a primary subject which is selected automatically or by manually focusing on the primary subject. Therefore, it is possible, with such a camera, to make proper prints from the original frames taken by such a high-precision camera, while printing at a constant print exposure amount, for example, for a constant print exposure time, which is predetermined according to the type of photographic paper and the print magnification, without measuring the density of each original frame for determining the respective print exposure amount.
However, if all the original frames are printed at a constant exposure time, photographic prints of some scenes which are, for various reasons, out of the functioning range of the automatic exposure control of the camera, would contain improperly finished images of the primary subjects therein. Such a case would arise, for example, when the density of the primary subject on the photographic film differs greatly from the average density of the original frame, as is described above.